Recently Fox announced that Mariah Carey is going to be the new Jennifer Lopez (but really the new Paula Abdul) in the 2013 edition of American Idol. In addition, country star Brad Paisley may take the slot recently abandoned by Steven Tyler (who was supposed to be the new Simon Cowell but more closely resembled Abdul in everything from wardrobe to demeanor). If the 11 seasons of Idol have taught us that reality-competition shows are like high school, they’ve also demonstrated that their judges are like your high school teachers. And if you wonder why so many of them are disappointing, just ask yourself which of your teachers you remember, and why.

Paula, Randy, Simon. The easy mark, the gym coach, the hard-ass. Abdul was the guidance counselor who filled you with self-affirmation that meant nothing to you because, despite the positive-thinking slogans tacked to her wall, she seemed like such a basket case that at least once before you graduated, you had to hug her and beg her to stop crying. Randy is the coach. Not the exemplary, tough, surrogate-dad coach of Friday Night Lights, but Scary Autopilot Coach, the guy who yelled everything with the same inscrutable combination of enthusiasm and threat. ”Hustle it up! Big day today! Way to hustle! Keep your head in it! Think on your feet! Big day today! Get in the game! Looking good!” After four years, you had no idea if he liked you or not. You suspect he didn’t know your name. And you are certain he never once gave you actual usable advice. And Simon was the teacher who never smiled, who radiated rageful disbelief that you weren’t bringing more to the table, who seemed personally insulted that you didn’t meet his expectations. When you finally sweated a term paper and saw the words ”Very nice work” in tiny, begrudging handwriting, you kept it for the next 11 years.

Reality shows need more Simons. I don’t mean Cowell himself, who slides too far into sneering sadism. But the best judges aren’t the ones who reassure contestants that at least they tried. Nobody goes on TV to get a certificate of attendance. And at home, on our couches, none of us are Paulas or Randys; we like judgment. We don’t watch Idol so we can shout at the TV, ”You look beautiful tonight!” or ”I dunno, dawg, you did your thing, I guess!” When Project Runway’s Nina Garcia says curtly that a garment would photograph well, it means something, because if someone puts ugly clothes in front of her, she will use words like ”hideous” and freeze them with a glare that says, If I were allowed to get out of this chair, you’d be in danger right now. When Top Chef’s Tom Colicchio is handed a plate of mediocre food, he’s never withering or nasty, but his disappointed-dad incomprehension — ”Did you taste this? Why would you serve this? You thought this was good enough?” — makes contestants bow their heads in shame.

Mariah Carey is in a tough place with Idol. (Please note that I am employing a rarely used meaning of ”tough place” that applies only to people making a reported $17 million a year.) She can’t go full Simon on contestants, because Idol is deploying her not just as a critiquer but also as the haloed embodiment of everything its contestants hope to become. But we don’t need another Christina Aguilera preeningly moaning on The Voice, ”This is sooo hard.” Women are always asked to be Glinda the Good Witch on these programs, and it never works. Next season, I’d love to see Carey say on camera what I am absolutely sure she will be saying off camera. If she has to serve as a role model, I hope the example she offers is about the value of high standards. And if that seems too scary for her, she should just channel Ms. Weiss, the character she played in Precious. A woman unafraid to tell off Mo’Nique is not going to sugarcoat things, and just might, against all odds, restore our long-eroded belief that when it comes to Idol, something is actually at stake.